One vertex per element, one color per generator, with an edge from x to x·s.
(1,2,4,5)(3,6,7,8)(17,18)(19,21)(20,22)(23,24)(25,26,28,32)(27,34,35,30)(29,31,37,33)(36,38,40,39)(2,5)(6,8)(9,10,12,14)(11,15,16,13)(17,19,20,23)(18,21,22,24)(25,27,28,35)(26,30,32,34)(29,36,37,40)(31,39,33,38)(9,11,12,16)(10,13,14,15)(26,31)(27,35)(29,37)(30,38)(32,33)(34,39)(1,3,4,7)(2,6,5,8)(18,22)(21,24)(26,32)(27,35)(31,33)(36,40)A Cayley diagram is a choice, not a fact about the group. Another drawing of this group — in a book, or on a different generating set — may look nothing like this one.